I bought a dC800 Maxx kit a couple months ago (the drama of that purchase available on another thread) because it is small, fits in one case, and was $1200.
It is enough to get me going.
My answer is in two parts.
Part 1) I am not a good enough diver to spend $5k buying a case for my Nikon D300 and the proper strobes and ports and stuff. By the time I get good enough, the D300 will be obsolete. DSLR cameras have a shelflife around my place of about 18 or so months (my wife's D80 is going on eBay tomorrow to be replaced by a D90).
Part 2) I believe that as long as you own a camera that has a decent lens on it (i.e. one that is reasonably sharp) and that has adequate lights, you can take amazing and fantastic pictures. It is the photographer that takes excellent pictures, not the camera.
Is a DC500, DC600, DC800 or DC1000 ever going to be as fast, versitile, responsive and flexible as a Nikon D300 with a good set of pro lenses in a quality case with a bunch of ports? No, of course not.
However, the real challenge isn't whether the gear is the best money can buy... it is whether the person taking the picture is the best photographer he can be.
I enjoy taking zoo pictures (as you can see on my website), and I get a lot of REALLY strange looks as I am carrying my two cameras that I use around the zoo... one is a Nikon D300 with a $1600 70-200 VR lens on it, and the other one is a Kodak Easyshare Z712IS that I bought on sale from Dell for $99 with a coupon. Some of my very best shots have come from using the Kodak, because it was the proper tool for the job.
Photographers tend to be gear heads. I can honestly say I don't fall into that category. Give me a reasonably sharp lens and some good quality light, and I am happy.